I have heard this argument before from the Caloric Restriction (CR) camp. I think it’s bunk. CR is like a cult though and they are very persuasive. Also their argument is that it is worth depriving yourself and eating 25%+ less than the average person in order to buy a few more years of crappy, deprived life.
Even his example is wrong. Marathon runners age faster due to higher metabolism? Sorry, runner here, and I am fairly certain that the running SLOWS my metabolism significantly and I suspect most other runners experience this too.